As regular CFZ-watchers will know, for some time Corinna has been doing a column for Animals & Men and a regular segment on On The Track... particularly about out-of-place birds and rare vagrants. There seem to be more and more bird stories from all over the world hitting the news these days so, to make room for them all - and to give them all equal and worthy coverage - she has set up this new blog to cover all things feathery and Fortean.

Tuesday, 26 April 2016

Beaks of Darwin’s finches evolve thanks to newly discovered gene

Named after the father of evolution himself, Darwin’s
finches played a pivotal role in helping Charles Darwin formulate and solidify
his theory of evolution. An already fascinating species of enormous importance,
the discovery of a rare gene just made these beautiful birds a good deal
more interesting than they already are.

Scientists were able to discover a gene that plays a role in
the shaping of the birds’ beaks. This gene, which is known as HMGA2, continues
to work in evolving the beaks of Darwin’s finches. And while Darwin didn’t
observe much change to his eponymous finches, biologists Peter and Rosemary
Grant were able to, having worked over four decades in the birds’ habitat of
the Galapagos Islands.

The story behind the discovery began about a decade ago, when
the husband-and-wife biologists observed a drought on Daphne Major Island,
which hosted two species of Darwin’s finch – the medium ground finch and the
large ground finch. The smaller of the two bird species (the medium finches)
didn’t attempt to compete with their larger equivalents due to the food
shortage that came with this event. Still, the medium ground finch was able to
outlive the large ground finch, with the average beak size for the former bird
decreasing quitter markedly. And that’s where the HMGA2 gene came in.